Hanging Valleys
A hanging valley is a tributary valley with the floor at a higher relief than the main channel into which it flows. They are most commonly associated with U-shaped valleys when a tributary glacier flows into a glacier of larger volume. The main glacier erodes a deep U-shaped valley with nearly vertical sides while the tributary glacier, with a smaller volume of ice, makes a shallower U-shaped valley. Since the surfaces of the glaciers were originally at the same elevation, the shallower valley appears to be ‘hanging’ above the main valley. Often, waterfalls form at or near the outlet of the upper valley. Hanging valleys are also the product of varying rates of erosion of the main valley and the tributary valleys. The varying rates of erosion are associated with the valleys rock composition of the adjacent rocks in the different valley locations. The tributary valleys are eroded and deepened by glaciers at a slower rate than that of the main valley floor. Thus the difference in the two valleys depth increases over time. The tributary valleys that were composed of more resistant rock then hangs over the main valley.
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Famous quotes containing the words hanging and/or valleys:
“the white eyes writhing in his face,
His hanging face, like a devil’s sick of sin;
If you could hear, at every jolt, the blood
Come gargling from the froth-corrupted lungs,
Obscene as cancer,”
—Wilfred Owen (1893–1918)
“The West is preparing to add its fables to those of the East. The valleys of the Ganges, the Nile, and the Rhine having yielded their crop, it remains to be seen what the valleys of the Amazon, the Plate, the Orinoco, the St. Lawrence, and the Mississippi will produce. Perchance, when, in the course of ages, American liberty has become a fiction of the past,—as it is to some extent a fiction of the present,—the poets of the world will be inspired by American mythology.”
—Henry David Thoreau (1817–1862)